Natural and Technological Risk Analysis in European Cross-Border Regions: An Integrated Approach to Hazards and Vulnerability.

Natural and technological disasters often have transboundary impacts, affecting multiple countries simultaneously, while the lack of joint preparedness and coordinated response mechanisms can significantly amplify damages and complicate recovery efforts. This study proposes an integrated methodology to assess transboundary hazards and population vulnerability across European cross-border regions. The framework combines georeferenced data on extreme weather events, wildfires, industrial areas, and nuclear power plants with a population-based vulnerability analysis. The results revealed pronounced spatial heterogeneity in transboundary hazards distribution across Europe. Extreme weather events affected most European border regions, with the highest values observed in central Europe and along the Portugal-Spain border. Wildfire hazards were strongly concentrated in southern and Mediterranean regions, particularly in the Iberian Peninsula and the Balkans. Technological hazards displayed a more localized pattern, with nuclear power plant-related hazards mainly concentrated in central European border regions and industrial hazards clustered in highly industrialized areas, notably in Belgium, the Netherlands, Germany, Italy, and Switzerland. The combined hazard analysis showed that the highest transboundary hazard levels occurred in regions where multiple hazards spatially co-occurred, such as the Italy-Switzerland, Belgium-the Netherlands, and Portugal-Spain borders, highlighting the importance of multi-hazard interactions. The assessment found that vulnerability was largely determined by population density and demographic structure, with the highest levels occurring in densely populated areas along the Belgium-Germany border. Overall, the proposed framework provides reproducible and policy-relevant evidence to support cross-border risk governance, coordinated prevention strategies, and emergency preparedness planning in Europe.